Aims and objectives: To describe our technique for performing radiofrequency ablation (RFA) in osteoid osteoma and to evaluate the results of treatment.

Materials and methods: We evaluated 40 patients in whom RFA was performed for osteoid osteomas between October 2005 and February 2008. The lesions were located in the femur (n = 22), tibia (n = 10), humerus (n = 2), acetabulum (n = 2), radius (n = 1), fibula (n = 1), patella (n = 1), and calcaneum (n = 1). The procedure was performed using a standard technique.

Results: Technical success was achieved in all patients, with intranidal localization of the needle and complete ablation. All patients were fully weight bearing 2-3 h after the procedure. Successful pain relief was achieved in all patients within 48 h. Immediate complications included a case of minor thermal skin burn and a small cortical chip fracture, which healed on its own. There were no delayed complications. The average follow-up period was 12 months. Two patients (5% of cases) had recurrence of pain after intervals of 5 and 8 months, respectively, following the ablation; this was due to recurrence of the lesion. Complete pain relief was however achieved after a second ablation in both cases. Thus, our primary and secondary clinical success rates were 95 and 100%, respectively.

Conclusion: RFA is a safe, quick, minimally invasive, and extremely effective method for the management of osteoid osteomas.

Mentions:
Early findings on imaging that suggested a successful procedure included the presence of an ablation tract and a ‘zone of ablation’ (due to coagulation necrosis) surrounding the tumor nidus on MRI [Figure 6]. Expected late findings on follow-up MRI at 1 year included sclerosis and regression of the lesion and reduction of the bone edema, with a well-demarcated low-signal zone of coagulation necrosis around the tumor nidus [Figure 7A]. After a successful procedure, contrast images showed a perfusion defect surrounded by a thin enhancing rim. [Figure 7B]. Follow-up CT scan did not reveal a significant change in the trabecular density.

Mentions:
Early findings on imaging that suggested a successful procedure included the presence of an ablation tract and a ‘zone of ablation’ (due to coagulation necrosis) surrounding the tumor nidus on MRI [Figure 6]. Expected late findings on follow-up MRI at 1 year included sclerosis and regression of the lesion and reduction of the bone edema, with a well-demarcated low-signal zone of coagulation necrosis around the tumor nidus [Figure 7A]. After a successful procedure, contrast images showed a perfusion defect surrounded by a thin enhancing rim. [Figure 7B]. Follow-up CT scan did not reveal a significant change in the trabecular density.

Bottom Line:
There were no delayed complications.The average follow-up period was 12 months.Thus, our primary and secondary clinical success rates were 95 and 100%, respectively.

Aims and objectives: To describe our technique for performing radiofrequency ablation (RFA) in osteoid osteoma and to evaluate the results of treatment.

Materials and methods: We evaluated 40 patients in whom RFA was performed for osteoid osteomas between October 2005 and February 2008. The lesions were located in the femur (n = 22), tibia (n = 10), humerus (n = 2), acetabulum (n = 2), radius (n = 1), fibula (n = 1), patella (n = 1), and calcaneum (n = 1). The procedure was performed using a standard technique.

Results: Technical success was achieved in all patients, with intranidal localization of the needle and complete ablation. All patients were fully weight bearing 2-3 h after the procedure. Successful pain relief was achieved in all patients within 48 h. Immediate complications included a case of minor thermal skin burn and a small cortical chip fracture, which healed on its own. There were no delayed complications. The average follow-up period was 12 months. Two patients (5% of cases) had recurrence of pain after intervals of 5 and 8 months, respectively, following the ablation; this was due to recurrence of the lesion. Complete pain relief was however achieved after a second ablation in both cases. Thus, our primary and secondary clinical success rates were 95 and 100%, respectively.

Conclusion: RFA is a safe, quick, minimally invasive, and extremely effective method for the management of osteoid osteomas.